Aug. 18: New website!. A brand new website is available. It is based on Jekill, should be readable on any device, has some dynamic flavor. It is the result of an effort to present my various interdisciplinary research activities in a hopefully more comprehensive way than the previous site (still available here).

Aug. 18: Enaction schools websites. Between 2006 and 2009 four summer schools on “Enaction and Cognitive Science” have been organized. The archive of their websites, with a lot of documents, is available here.

Jul. 18: Postdoc position in Experience modelling (french). We will have a french-speaking Postdoc position related to the HOMERIC project, starting in 2018, on qualitative / quantitative analysis and modelling of user experience in VR. (more info)

Leveraging Learners’ Activity Logs for Course Reading Analytics Using Session-Based Indicators (2018) Madjid Sadallah, Benoît Encelle, Azze-Eddine Maredj, Yannick Prié. in International Journal of Technology Enhanced Learning (to appear) Show abstract A challenge that course authors face when reviewing their contents is to detect how to improve their courses in order to meet the expectations of their learners. In this paper, we propose an analytical approach that exploits learners’ logs of reading to provide authors with insightful data about the consumption of their courses. We first model reading activity using the concept of reading-session and propose a new and efficient session identification. We then elaborate a list of indicators computed using learners’ reading sessions that allow to represent their behaviour and to infer their needs. We evaluate our proposals with course authors and learners using logs from a major e-learning platform. Interesting results were found. This demonstrates the effectiveness of the approach in identifying aspects and parts of a course that may prevent it from being easily read and understood, and for guiding the authors through the analysis and review tasks.

Progressive sequential pattern mining: steerable visual exploration of patterns with PPMT (2018) Vincent Raveneau, Julien Blanchard, Yannick Prié. in Visualization in Data Science (VDS at IEEE VIS 2018), Berlin, Germany, 2018. [AR:30%] Show abstract The progressive visual analytics (PVA) paradigm has been proposed to describe visual analytics systems whose main goal is to reach a thorough coupling between the analyst and her system by getting rid of waiting periods classically encountered during data processing. PVA systems use algorithms that both provide intermediate results throughout their execution, and are steerable by the analyst to change the strategy used to perform the remaining computation. Our focus is on progressive sequential pattern mining, as in the seminal work of Stolper et al. (2014). Here we go further mainly by considering the temporal nature of patterns related to their occurrences. We propose a pattern-oriented data model, a pattern analysis task model, and guidelines for designing progressive pattern mining algorithms. We introduce PPMT, a tool to support an analyst progressively explore activity traces, based on a modification of the GSP algorithm. We evaluate our proposal on the technical performances of our progressive algorithm, and on the effect of steering on analysts’ performances.

Axes and Coordinate Systems Representations for Immersive Analytics of Multi-Dimensional Data (2018) Adrien Fonnet, Toinon Vigier, Grégoire Cliquet, Fabien Picarougne, Yannick Prié. in 4th International Symposium on Big Data Visual and Immersive Analytics BDVA 2018, Konstanz, Germany, October 2018 Show abstract Axes are the main components of coordinate systems representations. They play a critical role for the visual analysis of multi-dimensional data. However their representation seems to have always be considered self evident, with oriented lines crossing at an origin, completed with labels such as ticks and names. Such classical representation show limits when it comes 3D visualization and immersive analytic (IA), mainly because orthogonal projection of points on linear axes is hard in a 3d environment, and because the user can move therefore the axes can get out of his field of view. In this paper we propose a task-based definition of axes and coordinate systems representation, as well as a tentative design space for coordinates systems representation in immersion. We also present an exploratory user study we carried out to compare three grid-based representations of coordinate systems for multidimensional data analysis with 3D scatterplots.